JP5221915B2 - Content management method, program thereof, and recording medium - Google Patents

Description

  The present invention relates to technology related to content management in a computer that manages the use of content that requires copyright protection such as digital broadcasting.

  Since the content provided by digital broadcasting is digital data, the quality does not deteriorate no matter how many times it is copied. Therefore, in Japan, restrictions are placed on copying in order to protect copyrights such as digital broadcasting.

  In Japan, a copy control signal of “copy once (can be recorded only once)” has been added to all programs in digital broadcasting since April 5, 2004. When a program is recorded by a terrestrial digital broadcast compatible HDD (Hard Disc) recorder or a personal computer (computer), the recording itself is counted as one copy. Therefore, when a copy of a program cannot be made and copied to a DVD (Digital Versatile Disc) for storage, it is performed only by a function called “move (or move out)” and recorded in the HDD (hard disk). The contents are erased. At this time, a DVD device that can be used for copying must be compatible with CPRM (Content Protection for Recordable Media).

  However, when content that requires copyright protection, such as digital broadcasting, is stored in the storage device of a personal computer, the content backed up by the backup software is restored to the hard disk after the move. There has been a problem that many copies of the content can be created by repeating restore and move.

  In Patent Document 1, in order to solve the above problem, an arbitrary value (information) is stored in a security area that cannot be reversibly updated among storage media (the stored information is referred to as “security area information”). The content stored in the rewritable area, the usage control information necessary for using the content, and the like are bound to the security area information. Then, a value at the time of binding (such as a hash value) is stored in a rewritable area, and it is determined that the content matching the value at the time of binding is valid. After that, when moving, the information in the security area is updated, rebound, the value at the time of binding is calculated again, and it is made different from the value before the move, thereby disclosing the above problem. Yes.

On the other hand, the current copy-once is not easy to use because the original data in the HDD is erased at the same time that the data once recorded on the HDD recorder is moved to a DVD or the like. In addition, there has been a problem that no data remains in both the HDD and DVD when the DVD is bad.
Therefore, a proposal to relax the mechanism of "copy once" and allow multiple copies is being studied by the review committee of the Ministry of Internal Affairs and Communications. For example, even if a digital broadcast is recorded on an HDD recorder and then copied to a recording medium such as a DVD, a portable player, or a game machine, the recorded data in the original HDD is not erased if the copy is made multiple times. However, re-copying from copied media is not possible, as it is now.

Even when copying is possible multiple times, the restrictions need to be strictly observed.
Japanese Patent Application Laid-Open No. 2004-151820 discloses a technique that manages the number of copies and the number of copy restrictions for each content based on the content management information, and prevents copying beyond the copy limit number. Furthermore, in order to prevent the content management information from being duplicated and used, it is disclosed that information for identifying that the content management information is the latest is managed by a hash value. The functions such as content management and content decryption processing are stored in a tamper-resistant module, and the content management information created by the content management processing is stored in a nonvolatile memory, thereby improving security. I am trying.
JP 2002-063074 (see paragraph 0012) JP 2007-150970 A (see paragraphs 0032 and 0050, FIG. 2)

  In this way, content management information important for content management needs to be stored in a secure storage area to prevent the problem that many copies of the content can be created, and not to be easily altered. At the same time, in practice, it is desirable to ensure a large storage capacity for recording content and to reduce the storage capacity for content management. Therefore, it is also a problem to reduce the secure storage area.

In order to solve the above-described problem, the present invention provides a content management method in a computer that manages the use of content that requires copyright protection, wherein the computer stores the content and content management information. A storage medium, a second storage medium that stores a check code corresponding to the content management information, and an update unit that updates the content management information every time the content stored in the first storage medium is used, Conversion means for newly generating the check code by applying the content management information to a predetermined formula every time content management information is updated, the check code stored before using the content, and using the content A check code newly generated by the conversion means from the content management information at the time of And a control unit that compares whether or not they match, and when the content is used, the update unit updates the content management information, and the content management information is stored in the first storage medium. Information is stored, the conversion means generates a check code corresponding to the updated content management information, stores the check code as the check code A in the second storage medium, and then uses the content In addition, the conversion unit applies the content management information stored in the first storage medium to a predetermined formula to newly generate the check code as a check code B, and the comparison unit generates the check code A and the check code A. If they match with the check code B, a move status flag included in the content management information is set, Executing a move-out indicating that the content stored in the first storage medium is recorded on a recording device connected to the computer, generating a check code of the content management information, and It is stored in the second storage medium, and it is determined whether or not the move-out is successful. If it is determined that the move-out is not successful, the data of the move-out destination is deleted, the move status flag is returned, and the move generating a check code corresponding to the content management information that returned the flag status, checksum and storing the check code in the second storage medium is further generated by applying the content to a predetermined formula A simple checksum generated using data at a specific location of the content is stored in the content management information. (1) When the content is moved, copied or deleted in the computer, or when the content is moved out, the updating means updates the content management information, and the first storage medium The content management information is stored in the second storage medium, and the conversion means generates a check code corresponding to the updated content management information, and stores the check code as the check code A in the second storage medium, (2) When reproducing or moving out the content, the check code A is acquired, and the conversion means applies the content management information stored in the first storage medium to a predetermined formula to convert the check code into the check code B. And the comparison means generates the check code A and the check code B. (3) In the case of further reproducing the content, when the comparison means compares the check code A with the check code B and the two match, the simple checksum read from the content management information And a simple checksum newly generated from the content to be reproduced and the two match, the reproduction of the content is permitted, and (4) the content is moved out, When the comparison means compares the check code A with the check code B and the two match, the checksum read from the content management information and the checksum newly generated from the content to be moved out are by comparing the case where both are coincident, allowing move-out of the content, And features.

  Content management information that is important for content management can be stored in a secure storage area and protected from being easily altered, and the secure storage area can be reduced (suppressing an increase in storage area). It becomes.

Embodiment
A content management system that manages the use of content that requires copyright protection will be described with reference to FIG. FIG. 1 is a diagram illustrating a content management system that manages the use of content that requires copyright protection.
The content management system 1 includes a tuner 10, a display device 30, a recording device 50, and a management device 60.
In addition, the management device 60 includes a decoding unit 20, a signal conversion unit 40, a processing unit 100 (control device), an encryption unit 130, a decryption unit 140, a storage device A200 (first storage medium), and a storage device B210 ( Second storage medium).
The processing unit 100 includes a content management unit 110 and a command control unit 120.

The tuner 10 has a function of selecting a specific channel from digital broadcasting and receiving a signal. It is assumed that it has a function of releasing scramble (encryption) originally applied to digital broadcasting.
The decoding unit 20 has a function of returning a signal output from the tuner 10 to a signal format that can be displayed on the display device 30.
The display device 30 is a television, a display, or the like, and has a function of displaying the output of the decoding unit 20 as a video.
When the recording device 50 is a recorder that records on a DVD, an SD memory card (registered trademark), a Blu-ray Disc (registered trademark), or the like, the signal conversion unit 40 inputs a signal suitable for each signal format. Has a function of converting the received signal.
The recording device 50 is a recorder that records on a DVD, an SD memory card (registered trademark), a Blu-ray Disc (registered trademark), and the like, and has a function of recording content on a movable storage medium.

The management device 60 has a function of managing the use of content. As described above, the management device 60 includes the decoding unit 20, the signal conversion unit 40, the processing unit 100, the encryption unit 130, the decryption unit 140, the storage device A200, and the storage device B210. In addition, the tuner 10, the display device 30, and the recording device 50 have a connection portion (not shown) for externally attaching. The management device 60 may be an HDD recorder or a personal computer (computer).
The encryption unit 130 encrypts video data output from the tuner 10 during recording. This is because, according to the regulations of ARIB (Association of Ratio Industries and Businesses), unencrypted high-definition video data should not be sent to a general-purpose bus such as a personal computer. Note that the encrypted video data is stored in the storage device A200.
The decryption unit 140 decrypts the video data stored in the storage device A200 during playback or move-out (move).
Note that the decoding unit 20, the signal conversion unit 40, the encryption unit 130, and the decoding unit 140 described above are configured by, for example, an LSI (ASIC) for a specific application.

The processing unit 100 includes a CPU (Central Processing Unit) and a RAM (Random Access Memory). In addition to the operating system, arithmetic programs and the like that are user programs are expanded and activated.
The processing unit 100 includes a content management unit 110 and a command control unit 120 as specific functions. The processing unit 100, the signal conversion unit 40, the recording device 50, the encryption unit 130, the decryption unit 140, the storage device A200, and the storage device B210 are connected via a bus so that information can be input and output. , Can be connected.

  The content management unit 110 updates the content management information every time the content stored in the storage device A200 is used, and applies the content management information to a predetermined formula each time the content management information is updated. Is compared with whether the check code stored in the storage device B210 before use of the content matches the check code generated from the content management information by the conversion unit when the content is used. And a comparison means. The content management information is stored in the storage device A200. Also, the check code corresponding to the content management information is stored in the storage device B210. The storage device B210 or the storage area in which the check code is stored is managed by dedicated software including authentication means that requires specific password information.

  The command control unit 120 receives instructions for use such as recording, playback, move-out (move), copy, delete, and move, and controls execution of a program corresponding to an operation instruction by the user. The move out (move) refers to moving the content stored in the storage device A200 to the recording device 50, and the recorded content stored in the storage device A200 is deleted. On the other hand, moving refers to changing a storage folder of content within the same personal computer.

The storage device A200 has a storage area managed by a folder path, and stores video data (content) and content management information. In addition, an ID unique to the apparatus is provided.
The storage device B (secure storage unit) 210 stores a check code corresponding to the content management information and an ID unique to the hard disk (ID of the storage device A200). In addition, the storage device B210 has an area that is managed by dedicated software including an authentication unit that requires specific password information and cannot be backed up by backup software. And the apparatus has a unique ID.

The secure storage device shown in the storage device B210 is realized by, for example, (i) a dedicated USB (Universal Serial Bus) device, (ii) another dedicated device, and (iii) an embedded device. Examples of other dedicated devices include flash memory. Examples of embedded devices include HDDs and SSDs (Solid State Discs).
The conditions of the realization method by these devices are demonstrated below.
(I) The conditions for the implementation method using a dedicated USB device are: a) the device can be authenticated, b) the stored data is encrypted, and c) the storage area cannot be accessed by the USB mass storage class driver. D) The flash device related to the storage area cannot be removed with a soldering iron (tamper resistance), e) The flash device related to the storage area cannot be rewritten by soldering etc. (tamper resistance) ).
(Ii) The conditions of the implementation method by other dedicated devices are: a) the device can be authenticated, b) the stored data is encrypted, c) the storage area can be accessed only by the dedicated driver, d) The storage device related to the storage area cannot be removed with a soldering iron (tamper resistance). e) The storage device related to the storage area cannot be rewritten by soldering (tamper resistance). It is.
(Iii) The conditions of the implementation method by the embedded device are: a) the stored data is encrypted, and b) the storage device related to the storage area cannot be removed with a soldering iron (tamper resistance). C) The storage device related to the storage area cannot be rewritten by soldering or the like (tamper resistance).

The flow of video data (content) will be described with reference to FIG. Note that the flow of video data is indicated by broken lines.
First, the video data selected by the tuner 10 is output from the tuner 10 after the scrambling originally applied to the digital broadcast is released.
When viewing directly without recording, the video data output from the tuner 10 is transmitted to the decoding unit 20 and displayed on the display device 30.
When recording, the video data output from the tuner 10 is encrypted by the encryption unit 130 and recorded in the storage device A200 via the bus.
When reproducing the recorded video data (content), the video data is read from the storage device A 200, decrypted by the decryption unit 140, and displayed on the display device 30 via the decoding unit 20. .
In the case of move-out, video data is read from the storage device A200 and recorded on a medium such as a DVD set in the recording device 50 via the decoding unit 140, the decoding unit 20, and the signal conversion unit 40. .

  Next, information stored in the storage device A200 and the storage device B210 and the relationship between the information will be described with reference to FIGS. FIG. 2 is a diagram illustrating a relationship between information recorded in the storage device A and information recorded in the storage device B. FIG. 3 is a diagram showing details of the content management information recorded in the storage device A.

As shown in FIG. 2, content management information and video data (content) are recorded in the storage device A200. The content management information is composed of common information and information for each content, details of which will be described later.
On the other hand, a check code generated by applying content management information to a predetermined formula is recorded in the storage device B210. As another method, a check code generated by applying information for each content in the content management information to a predetermined formula for each content may be stored.
Thus, by recording only the check code in the storage device B210, the storage capacity of the storage device B210 can be made very small compared to the storage capacity of the storage device A200 that stores the content management information. It becomes possible.

  For example, in content management information, common information requires a storage capacity of about 1024 bytes, and information for each content requires a storage capacity of about 1024 bytes per content. However, the check code corresponding to the content management information only needs 16 bytes. That is, if the number of contents is M, the check code corresponding to the entire content management information can reduce the storage capacity to 16 / (1024 × (M + 1)) = 1 / (64 × (M + 1)). .

Next, details of the content management information recorded in the storage device A200 will be described with reference to FIG. 3 (see FIG. 1 as appropriate).
As common information shown in FIG. 3A, an ID unique to a recording device (management device 60), an ID of a CPU (processing unit 100), an ID of a motherboard (main substrate), and an ID of a secure storage device (storage device B210) , Secure storage device link information, recording device registration time, total number of contents, and others (deletion, move-in information).
Among these pieces of common information, the link information of the secure storage device is a record of the storage device or folder path to which the check code is read / written as link information when the secure storage device is added. is there. The recording device registration time is, for example, the time when power is first turned on after purchase, the time when a clock is set, or the like.

As information for each content shown in FIG. 3B, checksum (for move), management checksum (for reproduction), folder path, storage device ID, move flag, move status, copy count, copy limit count, copy There are status, and others.
The checksum (for move-out) is a value generated by applying content to a predetermined formula for each content. And it is used for tampering check at the time of move out.
The simple checksum (for reproduction) is a value generated by extracting data at a plurality of specific locations from data of a single content. Therefore, since the simple checksum is generated in a shorter time than the checksum, the waiting time until the video is displayed after being played back can be shortened.
The folder path and the storage device ID are information for identifying the storage device and the folder path for recording the content.
The move flag is information for indicating that the move has been completed.
The move status is information for managing the execution of the move out by setting the flag of the move status during the execution of the move out, and lowering the flag when the move out is not executed. is there.
The copy count and copy limit count are information indicating the executed copy count and the set maximum copy count, respectively. Whenever copying is executed, these pieces of information are referred to, and if the number of copies exceeds the copy limit number, the copy function cannot be executed.
The copy status is information for managing the execution of copying by setting a flag of the copy status during execution of copying and lowering the flag when copying is not executed.
Others are preliminary information.

  Next, the flow of processing when executing recording, playback, move-out (move), copy, delete, and move will be described below.

(Recording)
The flow of processing when recording is selected in the command control unit 120 will be described with reference to FIG. FIG. 4 is a diagram showing the flow of processing when recording is selected. Note that “&” shown in the figure means “and”.
First, the content management unit 110 acquires content management information from the storage device A200 (step S301). Then, the content management unit 110 uses information such as an ID unique to a recording device, an ID of a CPU, an ID of a motherboard (main board), an ID of a secure storage device (here, storage device B210), and the like for content management. A key is created, and the created content management key is transmitted to the encryption unit 130 (step S302). The encryption unit 130 acquires content from the tuner 10 (step S303), encrypts the acquired content, and transmits it to the content management unit 110 and the storage device A200 (step S304). In step S304, the encryption unit 130 provides the content management unit 110 with information related to the folder path for the content storage location.

Next, the storage device A200 records the content transmitted from the encryption unit 130 (step S305). In addition, the content management unit 110 creates a checksum while receiving content (step S306).
When the recording in the storage device A200 is completed, the content management unit 110 updates the content management information (step S307) and records it in the storage device A200 (step S308). Further, the content management unit 110 creates a check code corresponding to the updated content management information (step S309) and records it in the storage device B210 (step S310). Incidentally, the check code recorded in step S310 (created in step S309) corresponds to the check code A.

  In FIG. 4, in step S304, the encrypted content is transmitted to both the content management unit 110 and the storage device A200. However, the present invention is not limited to this, and what is recorded in the storage device A200 is The content management unit 110 may read and create a checksum. Alternatively, on the contrary, it may be recorded in the storage device A200 via the content management unit 110. In any case, in this embodiment, recording in the storage device A200 and creation of a checksum are performed in parallel.

Here, the effect obtained by configuring the processing flow during recording as described above will be described below.
For example, by creating a checksum for each content in step S306, it is possible to easily confirm the validity of the content when performing a move-out. In steps S309 to S310, by recording a check code corresponding to the content management information including the checksum in the secure storage area, it is possible to reliably prevent unauthorized use of the content after recording.

(Regeneration)
The flow of processing when playback is selected in the command control unit 120 will be described with reference to FIG. FIG. 5 is a diagram showing the flow of processing when playback is selected. Note that “&” shown in the figure means “and”.
First, the content management unit 110 acquires content management information from the storage device A200 (step S321), and creates a new check code (check code B) by applying a predetermined formula (step S322). On the other hand, the content management unit 110 acquires a check code (check code A) recorded in advance from the storage device B210 (step S323). Then, the content management unit 110 compares the check code B created in step S322 with the check code A acquired in step S323, and determines whether or not they match (step S324).
If the check codes A and B do not match (No in step S324), the reproduction is not performed and the process ends. This is to prevent unauthorized reproduction.
On the other hand, if the check codes A and B match (Yes in step S324), a reproduction list is created based on the content management information (step S325) and displayed on the display device 30 (step S326). Note that when creating a playlist in step S325, if a move status or move flag is set (moveout is being executed or has been executed), or if no content is found, the playlist is not included in the playlist. Shall.

Then, the content management unit 110 receives the content name for reproduction selected based on the reproduction list displayed on the display device 30 (step S327). Next, the content management unit 110 reads the simple checksum (simple checksum A) recorded in advance in the content management information acquired in step S321 (step S328). On the other hand, the content management unit 110 acquires content (video data) corresponding to the received content name from the storage device A200, and creates a simple checksum (simple checksum B) (step S329). Then, the content management unit 110 compares the simple checksum (simple checksum A) read in step S328 with the newly created simple checksum (simple checksum B) in step S329, and whether or not they match. Is determined (step S330).
If the simple checksums A and B do not match (No in step S330), the reproduction is not performed and the process ends. On the other hand, if the simple checksums A and B match (Yes in step S330), the content management key for releasing the encryption is transmitted to the decryption unit 140 (step S331).

  Then, the decryption unit 140 acquires the content from the storage device A200 and executes decryption (step S332). Further, the decoding unit 20 converts the decoded signal into a display signal (step S333), and the display device 30 displays the video (step S334). When content is acquired from the storage device A200, the location of the content is acquired from the folder path of the content management information.

Here, an effect obtained by configuring the flow of processing during reproduction as described above will be described below.
For example, in step S324, by comparing the check code B newly created from the acquired content management information with the check code A read from the secure storage area, the validity of the content and the content management information can be easily determined. It becomes possible to confirm in a short time. In step S330, the simple checksum B newly created from the content stored in the storage device A200 is compared with the simple checksum A recorded in the content management information whose validity is confirmed. Playback can be started easily in a short time.

(Move out)
“Move out” refers to recording the content stored in the storage device A200 in the recording device 50.
Then, the flow of processing when move out (move) is selected in the command control unit 120 will be described with reference to FIG. FIG. 6 is a diagram showing the flow of processing when move-out is selected. Note that “&” shown in the figure means “and”.
First, the content management unit 110 acquires content management information and content from the storage device A200 (step S341). Then, the content management unit 110 newly creates a check code B from the acquired content management information (step S342). Next, the content management unit 110 acquires the check code A recorded in advance before the move-out from the storage device B210, which is a secure storage area (step S343). Then, it is compared whether or not the check code A and the check code B match (step S344).

If it is determined in step S344 that the check codes A and B do not match (No in step S344), the move-out is not executed and the process ends.
On the other hand, if the check codes A and B match (Yes in step S344), the content management unit 110 newly creates a checksum B from the content acquired in step S341 (step S345). Then, the content management unit 110 compares the checksum A read from the content management information acquired in step S341 with the checksum B created in step S345 (step S346).
If the checksums A and B do not match (No in step S346), the move-out is not executed and the process ends. On the other hand, if the checksums A and B match (Yes in step S346), the content management unit 110 sets a move status flag (sets it from 0 to 1) and executes the move out (step S347). That is, the move status of the content management information is changed. Then, the content management unit 110 creates a check code corresponding to the changed content management information (step S348) and records it in the storage device B210 (step S349). The check code recorded in step S349 corresponds to check code A, but is different from the check code acquired in step S343.

  Next, the content management unit 110 determines whether the move is successful or not (step S350). When the move is successful (Yes in step S350), the content management unit 110 sets the move flag (sets from 0 to 1), and lowers the move status flag (sets from 1 to 0) (step S351). Then, the content management unit 110 executes a process of deleting the content (recorded data) of the move source (Step S352), and deletes the content of the move source from the storage device A200 (Step S353).

  Next, the content management unit 110 updates the content management information (step S354) and records it in the storage device A200 (step S355). Further, the content management unit 110 creates a check code corresponding to the updated content management information (step S356) and records it in the storage device B210 (step S357). The check code recorded in step S357 corresponds to check code A, but is different from the check code acquired in step S343 and the check code recorded in step S349.

  On the other hand, if the move is not successful in step S350 (No in step S350), the data at the move destination is deleted and the move status is lowered (set from 1 to 0) (step S359). Then, the content management unit 110 creates a check code corresponding to the content management information with the move status lowered (step S360), and records it in the storage device B210 (step S361). The check code recorded in step S361 corresponds to the check code A, but is the same as the check code acquired in step S343 and is different from the check code recorded in step S349.

  In FIG. 6, 1 is set when the flag of the move status is set, and 0 is set when the flag is lowered. Also, the move flag is set to 1 when setting the flag in FIG. 6, but is not limited to this and may be set to be identifiable.

Here, as described above in [Problem to be Solved by the Invention], how to cope with the problem that a large number of copies of content can be created will be described below.
Now, the content Z and the content management information Y are backed up by the backup software, the move-out (first move-out) is executed, the content Z is restored, and the move-out (the second move-out that becomes illegal) ) Will be described.
When the first move-out is completed, the content management information is in a state where the flag of the move flag is set (set to 1) (step S351), and the content is deleted. (Steps S352 to S353). That is, the content management information is X (X ≠ Y) different from Y, and the check code A (X) corresponding to the content management information X is recorded in the storage device B210. Therefore, a check code B (Y) newly created in step S342 with respect to the content management information Y obtained at the time of step S341 in the second moveout, and a check code A (X) obtained in step S343. ) Is different from X ≠ Y. That is, in step S344, it is determined that the check codes A and B do not match, and the move-out cannot be executed.

In addition, the effect obtained by configuring the flow of processing at the time of move-out as described above will be described below.
For example, in step S344, by comparing the check code B newly created from the acquired content management information with the check code A read from the secure storage area, the validity of the content and the content management information can be easily determined. It becomes possible to confirm in a short time. Also, in step S346, the use of the content is reliably managed by comparing the checksum B newly created from the read content with the checksum A stored in the content management information whose validity has been confirmed. It becomes possible.

(Move)
“Move” refers to moving content to a storage area of a different folder path within the same management device 60. Therefore, it is different from the move out (move) for recording on the recording medium of the recording device 50.
The flow of processing when movement is selected in the command control unit 120 will be described with reference to FIG. FIG. 7 is a diagram showing the flow of processing when movement is selected.
As a premise of the migration process, it is assumed that the storage devices are connected to the same personal computer and have different IDs.
First, the content management unit 110 acquires content management information from the storage device A200 (step S381). Then, the content management unit 110 determines whether the movement has succeeded or not (step S382). If the move is not successful (No in step S382), the data at the move destination is deleted (step S389).
On the other hand, if the migration is successful (Yes in step S382), the folder path of the content management information and the storage device ID are rewritten (step S383) and recorded in the storage device A200 (step S384). Next, the content management unit 110 executes a process of deleting the source content (step S385) and deletes it from the storage device A200 (step S386). Then, a check code corresponding to the updated content management information is created (step S387) and recorded in the storage device B210 (step S388). The check code recorded in step S388 corresponds to check code A, but is different from the check code stored in storage device B210 at step S381.

Moreover, the effect by having comprised the flow of the process at the time of a movement as mentioned above is demonstrated below.
For example, since the movement is performed within the same personal computer, it is not necessary to check the validity of the content because the content is not particularly viewed when the movement is executed. For this reason, it is possible to immediately start the movement process without taking time to confirm the validity. Then, only when the movement is successful, the content management information is updated, and the check code corresponding to the updated content management information is recorded, so that it is possible to save the content management.

(copy)
Copying means creating a copy of the content.
The flow of processing when copying is selected in the command control unit 120 will be described with reference to FIG. FIG. 8 is a diagram showing the flow of processing when copy is selected.
First, the content management unit 110 acquires content management information from the storage device A200 (step S401). Then, the content management unit 110 extracts the copy count and the copy limit count from the content management information. Next, the extracted copy count is compared with the copy limit count (step S402). If the copy count is not smaller than the copy limit count (No in step S402), the copy is not executed and the process ends. On the other hand, if the copy count is smaller than the copy limit count (Yes in step S402), the copy is executed (step S403). If the copy is successful (Yes in step S404), the number of copies is increased by 1, the content management information is updated (step S405), and the content management information is recorded in the storage device A200 (step S406). . Also, a check code corresponding to the updated content management information is created (step S407) and recorded in the storage device B210 (step S408). The check code recorded in step S408 corresponds to check code A, but is different from the check code stored in storage device B210 at step S401.
On the other hand, if the copy is not successful in step S404 (No in step S404), the copy destination data is deleted (step S409).

The effects of configuring the processing flow during copying as described above will be described below.
For example, when copying is performed, since the content is not particularly viewed, the validity of the content is not confirmed. For this reason, it is possible to immediately start the copy process without taking time to confirm the validity. Then, only when the copying is successful, the content management information is updated, and the check code corresponding to the updated content management information is recorded, so that it is possible to save the content management.

(Delete)
Deletion means erasing content.
A flow of processing when deletion is selected in the command control unit 120 will be described with reference to FIG. FIG. 9 is a diagram showing the flow of processing when deletion is selected. Note that “&” shown in the figure means “and”.
First, the content management unit 110 acquires content management information from the storage device A200 (step S421). Then, the content management unit 110 executes processing for deleting the designated content (step S422), and deletes the designated content from the storage device A200 (step S423).
Next, the content management unit 110 deletes the management information related to the deleted content, decreases the total number by one, updates the content management information (step S424), and records it in the storage device A200 (step S425). Further, a check code corresponding to the updated content management information is created (step S426) and recorded in the storage device B210 (step S427). The check code recorded in step S427 corresponds to the check code A, but is different from the check code stored in the storage device B210 at the time of step S421.

The effect of configuring the processing flow at the time of deletion as described above will be described below.
For example, when executing deletion, the content is not particularly viewed, and therefore the validity of the content is not confirmed. Therefore, it is possible to immediately start the deletion process without taking time to confirm the validity. Then, only when the deletion is successful, the content management information is updated, and by recording a check code corresponding to the updated content management information, it is possible to save the content management.

Here, the storage capacity necessary for content management will be described below.
Information necessary for content management stored in the storage device B210 is at least a check code corresponding to the content management information and an ID unique to the hard disk in which the content and the content management information are recorded. For example, the capacity of the check code is 16 bytes and the ID of the hard disk is estimated to be 16 bytes. If the hard disk is replaced in place of the video cassette, the estimated number is 24 at most in a year, and if it is used for 10 years in the long term, it will be (16 bytes + 16 bytes) x 24 x 10 = 7680 bytes. . Even if the margin is further doubled, it is only 15360 bytes.
On the other hand, the content management information stored in the storage device A200 is about 1024 bytes per content.
Accordingly, the storage capacity can be greatly reduced by obtaining a check code by applying a predetermined formula to the content management information, and recording and managing the check code in a secure storage area (storage device B).

  As an effect of the present invention, content management is performed using check codes, so that it is possible to prevent unauthorized move-out and unauthorized copying. In addition, since content management can be performed properly, it is possible to disclose a right viewing right as a right viewing person. Since the viewing right can be shown, the content is distributed and viewed on another personal computer by a DLNA (Digital Living Network Alliance) server having a DTCP-IP (Digital Transmission Content Protection over Internet Protocol) function. Is possible. Furthermore, content can be stored in an existing hard disk simply by adding a secure storage device.

It is a figure which shows the content management system which manages utilization of the content which requires copyright protection. 4 is a diagram illustrating a relationship between information recorded in a storage device A and information recorded in a storage device B. FIG. 4 is a diagram showing details of content management information recorded in a storage device A. FIG. It is a figure which shows the flow of a process when recording is selected. It is a figure which shows the flow of a process when reproduction | regeneration is selected. It is a figure which shows the flow of a process when a move out is selected. It is a figure which shows the flow of a process when a movement is selected. It is a figure which shows the flow of a process when a copy is selected. It is a figure which shows the flow of a process when deletion is selected.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Content management system 10 Tuner 20 Decoding part 30 Display apparatus 40 Signal conversion part 50 Recording apparatus 60 Management apparatus 100 Processing part 110 Content management part 120 Command control part 130 Encryption part 140 Decoding part 200 Storage apparatus A
210 Storage device B

Claims (5)

A content management method for a computer that manages the use of content that requires copyright protection,
Computer
A first storage medium for storing the content and content management information;
A second storage medium for storing a check code corresponding to the content management information;
Updating means for updating the content management information every time the content stored in the first storage medium is used;
Conversion means for newly generating the check code by applying the content management information to a predetermined formula each time the content management information is updated;
Comparison means for comparing whether the check code stored before using the content matches the check code newly generated by the conversion means from the content management information when using the content; A control device comprising:
With
When the content is used, the update unit updates the content management information, stores the content management information in the first storage medium, and the conversion unit checks the check code corresponding to the updated content management information And storing the check code as the check code A in the second storage medium,
Next, when using the content, the conversion means applies the content management information stored in the first storage medium to a predetermined formula to newly generate the check code as a check code B, If the comparison means compares the check code A with the check code B and matches, the content stored in the first storage medium is set with a move status flag included in the content management information For the recording device connected to the computer to perform recording, generate a check code for the content management information, store the check code in the second storage medium,
It is determined whether or not the move-out is successful. If it is determined that the move-out is not successful, the data of the move-out destination is deleted, the move status flag is returned, and the move status flag is returned. generating a check code corresponding to, and storing the check code in the second storage medium,
Further, the content management information includes a checksum generated by applying the content to a predetermined formula and a simple checksum generated using data at a specific location of the content, and stores the checksum.
(1) When the content is moved, copied or deleted in the computer, or when the content is moved out, the updating unit updates the content management information, and the content management information is stored in the first storage medium. Storing, the conversion means generates a check code corresponding to the updated content management information, stores the check code as the check code A in the second storage medium,
(2) When playing back or moving out the content, the check code A is acquired, and the conversion means applies the content management information stored in the first storage medium to a predetermined expression to check the check code. Is newly generated as a check code B, and the comparison means compares the check code A with the check code B,
(3) Further, in the case of reproducing the content, when the comparison means compares the check code A with the check code B and the two match, the simple checksum read from the content management information, If both compare with the newly generated simple checksum from the content to be played back, allow playback of the content,
(4) Further, in the case of executing the move out of the content, when the comparison means compares the check code A with the check code B and the two match, the checksum read from the content management information , If both match when compared with a checksum newly generated from the content to be moved out, allowing the content to be moved out;
Content management method characterized by the above. An area in which the check code is stored is managed by dedicated software including an authentication unit that requires specific password information;
The content management method according to claim 1 . The check code is expressed by a smaller amount of information than the content management information;
The content management method according to claim 2 . The use of content requiring copyright protection is performed using a first storage medium that stores the content and content management information, and a second storage medium that stores a check code corresponding to the content management information. A content management program in a computer to be managed,
Computer
Updating means for updating content management information stored in the first storage medium each time the content stored in the first storage medium is used;
Conversion means for newly generating the check code by applying the content management information to a predetermined formula each time the content management information is updated;
Whether the check code stored in the second storage medium before use of the content matches the check code newly generated by the conversion means from the content management information when using the content A comparison means for comparing
Means for managing the area in which the check code is stored by dedicated software having authentication means that requires specific password information that cannot be backed up by backup software;
Means for expressing the check code by an amount of information smaller than the content management information by the predetermined formula;
Function as
When the content is used, the update unit updates the content management information, the content management information is stored in the first storage medium, and the conversion unit checks the check code corresponding to the updated content management information And storing the check code as the check code A in the second storage medium,
Next, when the content is used, the conversion unit applies the content management information to a predetermined formula to newly generate the check code as a check code B, and the comparison unit generates the check code A and the check code. If the code B is compared and the contents match, a moving status flag included in the content management information is set, and the recording device connected to the computer for the content stored in the first storage medium To execute a move-out indicating recording, generate a check code of the content management information, store the check code in the second storage medium,
It is determined whether or not the move-out is successful. If it is determined that the move-out is not successful, the data of the move-out destination is deleted, the move status flag is returned, and the move status flag is returned. Generating a check code corresponding to, and storing the check code in the second storage medium ,
Further, a checksum generated by applying the content to a predetermined formula and a simple checksum generated using data at a specific location of the content are included in the content management information and stored.
(1) When the content is moved, copied or deleted in the computer, or when the content is moved out, the updating unit updates the content management information, and the content management information is stored in the first storage medium. And storing the check code corresponding to the updated content management information, storing the check code as the check code A in the second storage medium,
(2) When playing back or moving out the content, the check code A is acquired, and the conversion means applies the content management information stored in the first storage medium to a predetermined expression to check the check code. Is newly generated as a check code B, and the comparison means compares the check code A with the check code B,
(3) Further, in the case of reproducing the content, when the comparison means compares the check code A with the check code B and the two match, the simple checksum read from the content management information, If both compare with the newly generated simple checksum from the content to be played back, allow playback of the content,
(4) Further, in the case of executing the move out of the content, when the comparison means compares the check code A with the check code B and the two match, the checksum read from the content management information , If both match when compared with a checksum newly generated from the content to be moved out, allowing the content to be moved out;
A content management program characterized by A computer-readable recording medium on which the content management program according to claim 4 is recorded.

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